/// <summary>
/// The method evaluates whether give name equals to the header name set
/// in the descriptor.
/// </summary>
/// <remarks>
/// This internal method detects its result by comparing the determined header
/// name either by using lower and upper cases or by ignoring it.
/// </remarks>
/// <param name="header">
/// The name to be compared.
/// </param>
/// <param name="exactly">
/// If true, then an case-sensitive string comparison is performed.
/// Otherwise as case-insensitive string comparison is performed.
/// </param>
/// <param name="descriptor">
/// The column descriptor to get header information from.
/// </param>
/// <returns>
/// True, if given name equals the header name within the descriptor,
/// and false if not.
/// </returns>
private static Boolean IsHeaderName(String header, Boolean exactly, ItemDescriptor descriptor)
{
String other = CsvImporter <TInstance> .GetHeaderName(descriptor);
StringComparison flags = exactly ? StringComparison.Ordinal : StringComparison.OrdinalIgnoreCase;
return(String.Compare(header, other, flags) == 0);
}
/// <summary>
/// This method tries to validate given headers by applying exact
/// validation rules.
/// </summary>
/// <remarks>
/// Exact validation rules means in detail that each string in given headers
/// must exactly match its corresponding header name. Furthermore, exactly
/// match means that each header name is compared by applying a case-sensitive
/// name check. It also means that each header position must be the same
/// position which is defined within given descriptors.
/// </remarks>
/// <param name="headers">
/// The list of header names to be validated.
/// </param>
/// <param name="descriptors">
/// The list of descriptors representing a single line.
/// </param>
/// <exception cref="FormatException">
/// This exception is thrown as soon as one of the header validation rules
/// has been violated.
/// </exception>
/// <exception cref="ArgumentOutOfRangeException">
/// This exception might be thrown if accessing the lists fails.
/// </exception>
private static void ValidateHeader(List <String> headers, List <ItemDescriptor> descriptors)
{
// Keep in mind, the column validation has already checked the column count. And it is trusted
// in that an Argument Out Of Range Exception is thrown if there was a made mistake beforehand.
for (Int32 index = 0; index < headers.Count; index++)
{
String header = headers[index];
ItemDescriptor descriptor = descriptors[index];
if (!CsvImporter <TInstance> .IsHeaderName(header, true, descriptor))
{
throw new FormatException(
$"Header validation mismatch. Header name \"{header}\" at column {index} does not fit " +
$"to the expected header name \"{CsvImporter<TInstance>.GetHeaderName(descriptor)}.\"");
}
}
}
